Embodiments of the invention relate generally to a semiconductor device packaging assembly and a method of making the same.
A common practice of packaging semiconductor dies involves mounting a single semiconductor die on a package substrate composed of laminate or organic materials, such as epoxy resins. More recently, experts in the field have introduced multi-die systems. In this practice, at least one or more semiconductor dies are positioned on a single package substrate. In some of these systems, one or more of the semiconductor dies may be high power devices, such as microprocessors, and others may be lower power devices, such as memory and voltage regulator devices.
As a result of having a hybrid package of high power and low power semiconductor dies, the thermal management apparatus of the package may require a thermal management mechanism such as a heat spreader in thermal contact with the semiconductor dies by way of thermal interface material layers. However, the varying thicknesses and tolerances of each component affect the thermal connection of the multi-die system. In addition, another level of tolerances can be introduced due to warping during the assembly process of these components. In turn, these varying dimensions can lead to a low yield from the completed package and manufacturing challenges.
The current state of the art attempts to protect a package, which has an exposed die during the assembly, from warping by introducing a metal ring to act as a stiffener 10, as shown in FIG. 1. FIG. 1 illustrates a semiconductor device package assembly 12 including stiffener 10 attached to a substrate 14 via an adhesive 16. In addition, a die 18 is attached to substrate 14. However, during the assembly process, package assembly 12 can face another level of warping due to the high temperature conditions of processes such as the reflow process. The warping is worse when the assembly introduces multi-die configurations.
FIG. 2 illustrates a semiconductor device package assembly 20 having a heat spreader 22, which is in contact with die 18 through a thermal interface material 24. Heat spreader 22 is further secured to stiffener 10 via adhesive 16. Due to warping during the assembly process and the differing thicknesses of the components, the thermal connection between heat spreader 22 and die 18 may not be appropriately established once heat spreader 22 is secured to stiffener 10, resulting in package assembly 20 having a low yield.
FIG. 3 depicts a semiconductor device package assembly 26 having multiple dies. In these configurations, one or more of the dies 18 may be high power devices, such as microprocessors, and others may be low power devices, such as memory and voltage regulator devices. As a result, the thermal management of assemblies having a hybrid of high power and low power dies 18 may require a thermal management mechanism such as heat spreader 22. Heat spreader 22 is in thermal contact with the semiconductor dies 18 by way of thermal interface material layers 24. Thermal interface material layers 24 can be solder-based, which has certain advantages for high powered devices due to the ability of solder to withstand higher temperatures and the greater thermal conductivity thereof. Thermal interface materials layers 24 may also be an organic material. However, under certain circumstances, the usage of heat spreader 22 with either organic or solder paste thermal interface material layers 24 can lead to additional warping.
As a result, there are many different scenarios during the assembly process of a semiconductor device package assembly that can lead to warping. Warping, in addition to the varying dimensions of multiple components, can lead to a low yield for the completed package. Therefore, it would be desirable to provide a flexible tolerance heat spreader that is able to be secured in a variety of locations along a support stud, as opposed to a single location atop a stiffener. This would allow the heat spreader to adapt its location in order to establish maximum thermal contact between the heat spreader and the components of the package assembly, resulting in being able to maintain the yield of a package even with the addition of multiple dies.